dildildil

hi guys i have a 06 a8l with 19in wheels but i dont think thats the problem... my car moves alot in the rear end specially if its rainy or when i go over bumps i feel the rear end move side to side alot what could it be ? its really dangerous on wet roads

thanks for help

mishar

First step is to align your wheels. Your rear alignment is probably off. While doing that guys should check if all suspension parts are OK.

MP4.2+6.0

+1

K9COP

It seems to me that our cars are particularly sensitive to rear end alignment, and you may find that it takes a couple of tries before you're comfortable with how the rear of the car 'feels'.. My car has 20's on it, and it took a few very subtle changes to rear alignment, and camber, before I was happy with how it felt. Assuming yours is factory, you may have another underlying issue going on, but believe me, it only takes the most subtle of changes to change the way it feels.

PM me if you want further alignment specs from my car, but that may not help yours on 19's. Mine's a shorty with sports package too...

K9

TSHong

I agree with everyone else. Check your suspension and alignment. Also something I just learned is if you have adaptive cruise, get your alignment done at the dealer. If someone adjust rear toe to much, it will throw the distance sensor alignment off. A dealer alignment covers that as well. I was wondering why the the body shop estimate stated a dealer alignment required only.

Bangerla

The rear doesnt have anything to do with the ACC sensor. During alignment, the steering wheel may have changed slightly, which causes the ACC problem. Just do a steering angle calibration, and it is fine.

dildildil

Hmmmm so its the alignment even though my car drives straight ? The problem im having is the rear end shifting side to side on wet roads and on bumps ....

I just want to make sure before I spend 180 and 2 hours on alignment only to find out its something else

Thanks again

mishar

Your toe angles are too big, but probably equal. Wheels are constantly pushing each either. On a dry flat road those forces annul each other, but on a bump or slightly slippery road one wheel gets upper hand and push the rear to the opposite side. Next moment the other one push harder so the rear goes the opposite way. So she wiggles.

TSHong

According to the manual, it does,

General information
The ACC adjustment may only be set using a VW/Audi-approved wheel alignment tester and adjustment device!

A correct adjustment is required for perfect ACC function.

Note: A new adjustment is necessary if:


•Rear axle toe is adjusted.
•The complete radar sensor is replaced.
•Cross member for bumper is loosened or adjusted.
•There is damage on the front end.

Special Tools and Equipment

•V.A.G 1813 Wheel alignment computer
•VAS 6190 or VAS 6041 and VAS 6041/1

snapdragon

Mine did this, I assumed something was worn at the rear so had it on a lift and it was all as sound as a pound, all original parts on 212,000miles.
I took to the dealer for alignment after replacing all front arms - the alignment was out on both sides at the rear and since adjusting that it no longer does this shimmy or squirm.
Sadly the front is toeing in too much slightly (just over limits) but the front rod adjustments were seized solid (original parts) but the dealer tech said if it was his car he would just leave it.